A MRCOOL DIY Series heat pump is the only ductless mini-split system on the market explicitly designed for amateur installation. You don't need special tools or training to install this high efficiency heat pump. The line sets precharged with R410A refrigerant, the quick hook-up electrical connections, and the quality engineering mean just about anyone can install a MRCOOL DIY in their home with no problem at all in only a few short hours. If you want great air comfort without paying an arm and a leg for installation, you want an easy-to-use MRCOOL DIY Series ductless heat pump.